Medium: water;900mL.

Apparatus 2: 50rpm.

Time: 30minutes.

Mobile phase— Dissolve 2.0g of monobasic potassium phosphate in water to make 1000mLof solution.Prepare a mixture of this solution and acetonitrile (600:400).Degas and filter through a filter having a porosity of 0.5µm or finer.Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).

Standard solution— Prepare a solution of USP Carteolol Hydrochloride RSin water having a known concentration of about 1.1Lµg per mL,Lbeing the labeled amount,in mg,of carteolol hydrochloride per Tablet.

Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a 252-nm detector and a 3.9-mm ×30-cm column containing packing L1.The flow rate is about 1mLper minute.Chromatograph the Standard solution,and record the responses as directed for Procedure:the relative standard deviation for replicate injections is not more than 2%.

Procedure— Filter a portion of the solution under test through a filter having a porosity of 1µm or finer,discarding the first 2mLof the filtrate.Separately inject equal volumes (about 15µL)of the Standard solutionand the test solution into the chromatograph,record the chromatograms,and measure the areas for the major peaks.Calculate the quantity,in mg,of C16H24N2O3·HC1dissolved by the formula: in which Cis the concentration,in µg per mL,of USP Carteolol Hydrochloride RSin the Standard solution,and rUand rSare the carteolol peak responses obtained from the test solution and the Standard solution,respectively.

Tolerances— Not less than 80%(Q)of the labeled amount of C16H24N2O3·HCl is dissolved in 30minutes.

pH6.0buffer ,Mobile phase,and Diluent—Proceed as directed in the Assayunder Carteolol Hydrochloride.

Standard solution— Dissolve an accurately weighed quantity of USP Dehydrocarteolol Hydrochloride RSquantitatively in Diluentto obtain a solution having a known concentration of about 1µg per mL.

Test solution— Weigh and finely powder not less than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 10mg of carteolol hydrochloride,to a 100-mLvolumetric flask,add about 50mLof Diluent,and shake by mechanical means for 1hour.Dilute with Diluentto volume,and mix.Filter about 5mLof this solution through a filter having a 0.5-µm or finer porosity.

Chromatographic system (see Chromatography á621ñ)—The liquid chromatograph is equipped with a fluorometric detector,with excitation at 300nm and a 418-nm emission filter,and a 3.9-mm ×30-cm column that contains packing L1.The flow rate is about 2mLper minute.Chromatograph the Standard solution,and record the peak responses as directed for Procedure:the relative standard deviation for replicate injections is not more than 5%.

Procedure— [NOTE—Use peak areas where peak responses are indicated.]Separately inject equal volumes (about 20µL)of the Standard solutionand the Test solutioninto the chromatograph,record the chromatograms,and measure the dehydrocarteolol peak responses.Calculate the percentage of dehydrocarteolol hydrochloride in the portion of Tablets taken by the formula: in which Cis the concentration,in µg per mL,of USP Dehydrocarteolol Hydrochloride RSin the Standard solution,Lis the labeled amount,in mg,of carteolol hydrochloride in each Tablet,WAis the average weight,in mg,of each Tablet,WTis the quantity,in mg,of the portion of Tablets taken to prepare the Test solution,and rUdand rSdare the dehydrocarteolol peak responses obtained from the Test solutionand the Standard solution,respectively.Not more than 1.0%is found.

pH6.0buffer ,Mobile phase,Diluent,Standard preparation,Resolution solution,and Chromatographic system—Proceed as directed in the Assayunder Carteolol Hydrochloride.

Assay preparation— Weigh and finely powder not less than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 10mg of carteolol hydrochloride,to a 100-mLvolumetric flask.Add about 50mLof Diluent,and shake by mechanical means for 1hour.Add 5mLof acetonitrile,dilute with Diluentto volume,and mix.Filter a portion of this solution through a filter having a 0.5-µm or finer porosity,discarding the first 2mLof filtrate,and use the clear filtrate as the Assay preparation.

Procedure— [NOTE—Use peak areas where peak responses are indicated.]Separately inject equal volumes (about 20µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the quantity,in mg,of C16H24N2O3·HCl in the portion of Tablets taken by the formula: in which Cis the concentration,in mg per mL,of USP Carteolol Hydrochloride RSin the Standard preparation,and rUand rSare the carteolol peak responses obtained from the Assay preparationand the Standard preparation,respectively.